Scalar-Tensor theories from Λ(ϕ)\Lambda(\phi) Plebanski gravity

We study a modification of the Plebanski action, which generically corresponds to a bi-metric theory of gravity, and identify a subclass which is equivalent to the Bergmann-Wagoner-Nordtvedt class of scalar-tensor theories. In this manner, scalar-tensor theories are displayed as constrained BF theories. We find that in this subclass, there is no need to impose reality of the Urbantke metrics, as also the theory with real bivectors is a scalar-tensor theory with a real Lorentzian metric. Furthermore, while under the former reality conditions instabilities can arise from a wrong sign of the scalar mode kinetic term, we show that such problems do not appear if the bivectors are required to be real. Finally, we discuss how matter can be coupled to these theories. The phenomenology of scalar field dark matter arises naturally within this framework.Comment: 21 page

A cross-sectional survey on the lifestyle and healthseeking behaviour of Basotho patients with diabetes

Objectives: The objectives of the study were to determine the level of practice of a healthy lifestyle, to assess the health education provided to patients with diabetes and to determine the prevalence of obesity among Basotho patients with diabetes.Design: A cross-sectional study enrolled 192 patients between November 2004 and July 2005. Descriptive statistics on demographic, socio-economic and lifestyle data were computed. Weight, waist circumference and hip circumference measurements were taken to compute body mass index (BMI), waist-to-hip ratio (WHpR) and waist-to-height ratio (WHtR). Setting and subjects: Patients with diabetes attending three hospitals in Lesotho were recruited in the study. Outcome measures: These included obesity indices, the quality and quantity of physical exercises, the quality and quantity of provided health education and the frequency with which the subjects sought medical help.Results: The participants’ mean age was 54.73 years. The prevalence of smoking (14.6%) was higher than that of drinking (9.4%). Only 20.8% of the participants participated in recommended physical exercise. Most participants (95%) consulted their physicians on a regular basis. The Health Education Quantity Index was very low: 49.9%. The prevalence of obesity measured by BMI, WHpR and WHtR was 67.7%, 69.8% and 95.3% respectively.Conclusion: The practice of a healthy lifestyle was suboptimal, but help-seeking behaviour was satisfactory among participants. It is recommended that health education and the promotion of a healthy lifestyle are encouraged, that diabetes education is rendered by accredited educators or healthcare providers trained in communicating health messages, and that the fight against obesity is made a priority.Keywords: diabetes, health education, health-seeking behaviour, body mass index, hip circumference, waist to hip ratio, waist to height rati

Prediction of sleepiness ratings from voice by man and machine

This paper looks in more detail at the Interspeech 2019 computational paralinguistics challenge on the prediction of sleepiness ratings from speech. In this challenge, teams were asked to train a regression model to predict sleepiness from samples of the Düsseldorf Sleepy Language Corpus (DSLC). This challenge was notable because the performance of all entrants was uniformly poor, with even the winning system only achieving a correlation of r=0.37. We look at whether the task itself is achievable, and whether the corpus is suited to training a machine learning system for the task. We perform a listening experiment using samples from the corpus and show that a group of human listeners can achieve a correlation of r=0.7 on this task, although this is mainly by classifying the recordings into one of three sleepiness groups. We show that the corpus, because of its construction, confounds variation with sleepiness and variation with speaker identity, and this was the reason that machine learning systems failed to perform well. We conclude that sleepiness rating prediction from voice is not an impossible task, but that good performance requires more information about sleepy speech and its variability across listeners than is available in the DSLC corpu

Constructive factorization of LPDO in two variables

We study conditions under which a partial differential operator of arbitrary order $n$ in two variables or ordinary linear differential operator admits a factorization with a first-order factor on the left. The factorization process consists of solving, recursively, systems of linear equations, subject to certain differential compatibility conditions. In the generic case of partial differential operators one does not have to solve a differential equation. In special degenerate cases, such as ordinary differential, the problem is finally reduced to the solution of some Riccati equation(s). The conditions of factorization are given explicitly for second- and, and an outline is given for the higher-order case.Comment: 16 pages, to be published in Journal "Theor. Math. Phys." (2005

Laser-induced optical changes in amorphous multilayers

It is shown that the well-known blue-shift of the fundamental absorption edge in as-deposited compositionally modulated amorphous Si/Ge and As6Se94/Se80Te20 multilayers (with periods of 4-8 nm) is further enhanced due to the thermal or laser-induced intermixing of adjacent layers. The laser-induced intermixing process, as supported by experiments and model calculations, can be attributed to both the local heating and photo-effects in As6Se94/Se80Te20 multilayers, while only the thermal effects were observed for Si/Ge multilayers. Structural transformations, based on this enhanced interdiffusion, provides good capability for spatially patterning optoelectronic devices and digital information recording

Thrust characteristics of a series of convergent-divergent exhaust nozzles at subsonic and supersonic flight speeds

An experimental investigation of a series of four convergent-divergent exhaust nozzles was conducted in the Lewis 8-by-6 foot supersonic wind tunnel at Mach numbers of 0.1, 0.6, 1.6, and 2.0 over a range of nozzle pressure ratios. The thrust characteristics of these nozzles were determined by a pressure-integration technique. From a thrust standpoint, a nozzle designed to give uniform parallel flow at the exit had no advantage over the simple geometric design with conical convergent and divergent sections. The rapid-divergent nozzles might be competitive with the more gradual-divergent nozzles since the relatively short length of these nozzles would be advantageous from a weight standpoint and might result in smaller thrust losses due to friction. The thrusts, with friction losses neglected, were predicted satisfactorily by one-dimensional theory for the nozzles with relatively gradual divergence. The thrusts of the rapid-divergent designs were several percentages below the theoretical values at the design pressure ratio or above, while at low pressure ratios there was a considerable effect of free-stream Mach number, with thrusts considerably above theoretical values at subsonic speeds and somewhat above theoretical values at supersonic speeds. This Mach numb effect appeared to be related to the variation of the model base pressure with free-stream Mach number

It Sounds Like You Have a Cold! Testing Voice Features for the Interspeech 2017 Computational Paralinguistics Cold Challenge

This paper describes an evaluation of four different voice feature sets for detecting symptoms of the common cold in speech as part of the Interspeech 2017 Computational Paralinguistics Challenge. The challenge corpus consists of 630 speakers in three partitions, of which approximately one third had a “severe” cold at the time of recording. Success on the task is measured in terms of unweighted average recall of cold/not-cold classification from short extracts of the recordings. In this paper we review previous voice features used for studying changes in health and devise four basic types of features for evaluation: voice quality features, vowel spectra features, modulation spectra features, and spectral distribution features. The evaluation shows that each feature set provides some useful information to the task, with features from the modulation spectrogram being most effective. Feature-level fusion of the feature sets shows small performance improvements on the development test set. We discuss the results in terms of the most suitable features for detecting symptoms of cold and address issues arising from the design of the challenge

Revision of the Upper Cretaceous ammonite fauna of the Bakony Mountains (Hungary)

A revision of the ammonites from the Bakony Mountains (Hungaty) based on collections of the Geological Institute of Hungary (MAFI) in Budapest, revealed the following sequence of faunas. The youngest Campanian ammonites from the South Bakony are three specimens ofPachydiscus (P.)praecolligatus COLLIGNON, 1955 from the Siimeg area; this is a typical Campanian species. Two specimens of former "Lower Maastrichtian Pachydiscus neubergicus (HAUER)" from Haraszt quany have been re-determined as Early Campanian Eupachydiscus levyi (GROSS OUVRE, 1894). The fragmentary specimen of Mortoniceras sp. has been determined as Texanites (Texanites) sp. from the Upper Santonian. Two ammonite zones can be recognised for these sequences: Texanites sp. (Santonian) and Eupachydiscus levyi (Lower Campanian)